Blogging with Sharepoint is painful. A couple of reasons:
1) SLOW. Part of this can be the server it is on, or the bandwidth and latency between here and there. But even on a fast server sitting next to you, the interface is a) coded inefficiently, and b) slow and awkward to use.
2) Not open. A web application falls several notches right off the bat if I can't use the browser of my choice as an equal citizen. In Sharepoint's case (at least, with this version), I can open a page and create a post in a browser such as Google Chrome, but I have no access to the WYSIWIG tools for working with the post that Internet Explorer gets. Adhering to open standards has accessibility benefits way beyond which browser you can use - searchability and usability jump way up.
related: See my post on IE6 and how it causes untold headaches in IT: http://voltage.bstonetech.com/blog/2010/01/its-time-to-stop-using-ie6-ed-bott’s-microsoft-report-zdnet-com/ (note: the linked article barely even touches on the coding nightmare having IE6 as a lowest common denominator brings about)